Detent means for cable drums



- I Sept. 8, 1 936. F AHL 2,053,976

DETENT MEANS FOR CABLE DRUMS Original Filed March 1, 1933 mlllmmnInven%07; I FRANK E. STAN-L Patented Sept. 8,

UNITED STATES PATENT OFFICE DETENT MEANS FOR CABLE DRUlWS Originalapplication March 1, 1933, Serial No. 659,113. Divided and thisapplication July 6,

1935, Serial No. 30,180

2 Claims.

My invention relates in general to hoist drums, and particularly tomeans for stopping the rotation of the drum when the cable carriedthereby has become substantially unwound therefrom.

This application is a division of application Serial No. 659,113, filedMarch 1, 1933 upon Means for preventing reverse winding of a cable on adrum, which issued November 13, 1934 in Letters Patent No. 1,980,935.

It is well known to those skilled in the art that when operated a wirerope drum hoist, there is a tendency for the operator to keep revolvingthe drum after the last turn of cable has been unwound therefrom,thereby causing the cable to start winding upon the drum in the reversedirection. This is not only liable to cause serious damage to the hoistor to the load being handled, but such a condition makes the cable unfitfor further use, since when hoisting cable is wound in the wrongdirection upon a drum, it is kinked in such a manner that the kinkcannot be removed.

The principal object of my invention has been to provide means forpositively stopping the drum when the cable has been substantiallyunwound therefrom so as to make it impossible to revolve the drum anyfurther in a lowering or unwinding direction.

Moreover, my invention does not in any wise affect the normal operationof the hoist and it is automatic in its action.

Furthermore, my invention may be applied to the cable drum of anyhoisting apparatus, and it :is so inexpensive that it does not addmaterially to the cost of the equipment.

The above objects and advantages have been accomplished by the deviceshown in the accompanying drawing, of which:

Fig. l is a side, sectional elevation of my invention, and is taken online ll of Fig. 2.

Fig. 2 is a front elevation of the device showing the drum in theposition it will occupy when rotated ninety degrees in counterclockwisedirection, as viewed in Fig. 1.

Fig. 3 is a fragmentary, sectional view showing a position of the detentlever when the first turn of cable is being wound upon the drum.

My device comprises a drum l which is rigidly mounted upon a suitableshaft II. The shaft II is, of course, mounted in suitable bearings l2each carried by a bracket [3.

The drum is provided with a body 15 and end flanges l6 and H. The bodyof the flange is preferably provided with a helical guide groove l8.

The cable 20 has its inner end passing into the body I of the drumthrough an opening 2| formed at the inner end of the guide groove l8,near the flange ll. So as to carry the cable smooth into the interior ofthe drum, the guide groove terminates in an inwardly curved wall 22. Asuitable anchor 23 is provided on the extreme inner end of the cable andthis serves to secure the end of the cable to the drum.

The body of the drum is formed with a recess 25 which is so located thatit lies in the first turn of the guide groove l8 and underneath thefirst turn of the cable when wound upon the drum. A detent lever 26 isarranged to lie in the recess 25 and is pivotally carried by means of apivot pin 2i secured to the body. The outside surface of the detentlever is preferably curved so as to be concentric with the guide groovel8 when it lies in the recess 25, so that the cable, as it is Woundaround the first turn of the groove, will be supported by the lever andthe lever will be held within the recess by the cable. The pivot pin 21is arranged at the end of the recess 25 which is in. the advance whenthe drum is being rotated to wind the cable thereon. The end of therecess 25 at which the pivot 21 is formed is provided with a shoulder 28which forms an abutment when the detent lever is in the position shownin Fig. 1, thus preventing the lever from moving farther around upon itspivot.

The bracket I3 is provided with a downwardly extending detent arm 30carrying a detent lug 3|. The detent lug extends beyond the inner faceof the end flange ll of the drum and is engaged by the free end 29 ofthe detent lever 26 when the lever falls out of the recess 25 andoccupies the position shown in Fig. 1.

From the foregoing it will be obvious that when the'drum I0 is rotatedin a counterclockwise direction from the position shown'in Fig. 1, andas viewed in that figure, the detent lever 26 will be elevated and willbe moved into the recess 25 by gravity, having substantially reached itsinner position when the drum has been rotated to the position shown inFig. 2. Upon continued rotation, the first coil of cable would be laidover the detent lever 26 as it lies within its recess 25, as clearlyshown in Fig. 3, thus holding the detent lever within the recess andpreventing its falling out of the drum. When, however, the drum isrotated in a clockwise direction to unwind the cable, and the last turnof cable on the drum has been reached, as shown in Fig. 3, furtherclockwise movement will cause the detent lever to be uncovered and bringit to the position shown in Fig. 2. When in this position, furtherrotation of the drum will permit the lever to move by gravity out of therecess and to engage with the detent lug 3| when the free end 29 of thelever has been lowered, by the continued rotation of the drum, to theposition where it will contact with such detent, as clearly shown inFig. 1. Further clockwise or unwinding movement of the drum is therebystopped and all possibility of rewinding the cable upon the drum inopposite direction with the consequent kinking of the cable. ispositively prevented.

Obviously, some modifications of the details herein shown and describedmay be made without departing from the spirit of my invention or thescope of the appended claims, and I do not, therefore, wish to belimited to the exact embodiment of the invention as herein shown anddescribed.

Having thus described my invention, what I claim is:

l. The combination with a drum and a cable therefor, of detent means forthe cable drum, comprising a bearing bracket for the drum, the drumbeing formed with a recess in its periphery, a gravity actuated latchlever nested in the recess of the drum when held therein by the cable,said lever being pivotally attached to the drum, said cable beingengageable with the latch lever to hold the same in inoperative positionuntil the same is substantially completely unwound therefrom, and adetent lug carried by the bracket and engageable with the latch when thesame is released from the recess.

2. The combination with a drum and a cable therefor, of detent means forthe cable drum, comprising a bearing bracket for the drum, the drumbeing formed with a recess in its periphery, a gravity actuated latchlever mounted in the recess of the drum and pivotally attached to thedrum, said cable being engageable with the latch to hold the same ininoperative position until the sameis substantially completely unwoundthere'irom, a detent lug carried by the bracket and engageable with thelatch lever when the same is released from the recess, and a shoulder 20

